autopas::AutoTuner Class Reference

This class manages all logic related to the auto tuning mechanic. More...

#include <AutoTuner.h>

Public Types
using	TuningStrategiesListType = std::vector< std::unique_ptr< TuningStrategyInterface > >
	Type for the member holding all tuning strategies.
using	SearchSpaceType = std::set< Configuration >
	Type for the search space holding all possible configurations.

Public Member Functions
	AutoTuner (TuningStrategiesListType &tuningStrategies, const SearchSpaceType &searchSpace, const AutoTunerInfo &autoTunerInfo, unsigned int rebuildFrequency, const std::string &outputSuffix)
	Constructor for the AutoTuner that generates all configurations from the given options.
AutoTuner &	operator= (AutoTuner &&other) noexcept
	Move assignment operator.
void	forceRetune ()
	Force the internal tuner to enter a new tuning phase upon the next call to computeInteractions().
const TuningMetricOption &	getTuningMetric () const
	Getter for the primary metric for tuning.
void	receiveLiveInfo (const LiveInfo &liveInfo)
	Pass live info on to all tuning strategies.
bool	needsHomogeneityAndMaxDensityBeforePrepare () const
	Indicator whether tuner needs homogeneity and max density information before the next call to prepareIteration().
bool	prepareIteration ()
	Determines what live infos are needed and passes collected live info to the tuning strategies.
void	bumpIterationCounters (bool needToWait=false)
	Increase internal iteration counters by one.
bool	willRebuildNeighborLists () const
	Returns whether rebuildNeighborLists() should be triggered in the next iteration.
const Configuration &	getCurrentConfig () const
	Get the currently selected configuration.
std::tuple< Configuration, bool >	getNextConfig ()
	Ask the tuner for the next configuration to use.
std::tuple< Configuration, bool >	rejectConfig (const Configuration &rejectedConfig, bool indefinitely)
	Tell the tuner that the given config is not applicable.
bool	searchSpaceIsTrivial () const
	Indicator function whether the search space consists of exactly one configuration.
bool	searchSpaceIsEmpty () const
	Indicator function whether the search space has no configurations in it.
void	logTuningResult (bool tuningIteration, long tuningTime) const
	After a tuning phase has finished, write the result to a file.
bool	initEnergy ()
	Initialize pmt sensor.
bool	resetEnergy ()
	Reset the rapl meter to prepare for a new measurement.
std::tuple< double, double, double, long >	sampleEnergy ()
	Take an energy measurement.
void	addMeasurement (long sample, bool neighborListRebuilt)
	Save the runtime of a given traversal.
void	addHomogeneityAndMaxDensity (double homogeneity, double maxDensity, long time)
	Adds measurements of homogeneity and maximal density to the vector of measurements.
const std::vector< Configuration > &	getConfigQueue () const
	Getter for the current queue of configurations.
const std::vector< std::unique_ptr< TuningStrategyInterface > > &	getTuningStrategies () const
	Get the list of tuning strategies that are used.
bool	inTuningPhase () const
	Indicate if the tuner considers itself currently in a tuning phase according to its internal counters.
bool	inFirstTuningIteration () const
	Indicate if the tuner is in the first iteration of a tuning phase.
bool	inLastTuningIteration () const
	Indicate if the tuner is in the last iteration of the tuning phase.
const EvidenceCollection &	getEvidenceCollection () const
	Getter for the internal evidence collection.
bool	canMeasureEnergy () const
	Returns whether the AutoTuner can take energy measurements.
void	setRebuildFrequency (double rebuildFrequency)
	Sets the _rebuildFrequency.
void	checkEarlyStoppingCondition ()
	Checks whether the current configuration performs so poorly that it shouldn't be resampled further within this tuning phase.

Detailed Description

This class manages all logic related to the auto tuning mechanic.

This involves:

• Managing the search space and configQueue.
• Managing and triggering all active tuning strategies.
• Managing all collected evidence and passing it to the strategies.

The tuner can be in one of two states. If it currently should look for a new optimum, it is in the so-called tuning phase. During a tuning phase, for each Configuration, multiple measurements can be taken, which are called samples. To reduce noise, the samples for one configuration are then condensed to one value for the current tuning phase, called evidence. The evidences are handed on to a tuningStrategy, which selects a) what Configuration to test next and b) which configuration is the best in this tuning phase. If it should not look for a new optimum it is not in a tuning phase.

Constructor & Destructor Documentation

AutoTuner()

autopas::AutoTuner::AutoTuner	(	TuningStrategiesListType &	tuningStrategies,
		const SearchSpaceType &	searchSpace,
		const AutoTunerInfo &	autoTunerInfo,
		unsigned int	rebuildFrequency,
		const std::string &	outputSuffix
	)

Constructor for the AutoTuner that generates all configurations from the given options.

Parameters

tuningStrategies	Vector of object implementing the modelling and exploration of a search space. Will be moved into the tuner.
searchSpace	All possible configurations.
autoTunerInfo	Struct containing more configuration information.
rebuildFrequency	The number of iterations after which the neighbor lists are rebuilt.
outputSuffix	Suffix for all output files produced by this object.

Member Function Documentation

addHomogeneityAndMaxDensity()

void autopas::AutoTuner::addHomogeneityAndMaxDensity	(	double	homogeneity,
		double	maxDensity,
		long	time
	)

Adds measurements of homogeneity and maximal density to the vector of measurements.

Parameters

homogeneity
maxDensity
time	Time it took to obtain these measurements.

addMeasurement()

void autopas::AutoTuner::addMeasurement	(	long	sample,
		bool	neighborListRebuilt
	)

Save the runtime of a given traversal.

Samples are collected and reduced to one single value according to _selectorStrategy. Only then the value is passed on to the tuning strategy. This function expects that samples of the same configuration are taken consecutively. The sample argument is a long because std::chrono::duration::count returns a long.

Parameters

sample
neighborListRebuilt	If the neighbor list as been rebuilt during the given time.

bumpIterationCounters()

void autopas::AutoTuner::bumpIterationCounters

(

bool

needToWait = false

)

Increase internal iteration counters by one.

Should be called at the end of an iteration.

Parameters

needToWait

If tuner should wait for other tuners.

canMeasureEnergy()

bool autopas::AutoTuner::canMeasureEnergy

(

)

const

Returns whether the AutoTuner can take energy measurements.

Returns

checkEarlyStoppingCondition()

void autopas::AutoTuner::checkEarlyStoppingCondition

(

)

Checks whether the current configuration performs so poorly that it shouldn't be resampled further within this tuning phase.

If the currently sampled configuration is worse than the current best configuration by more than the earlyStoppingFactor factor, it will not be sampled again this tuning phase. Uses the _estimateRuntimeFromSamples() function to estimate the runtimes.

forceRetune()

void autopas::AutoTuner::forceRetune

(

)

Force the internal tuner to enter a new tuning phase upon the next call to computeInteractions().

getConfigQueue()

const std::vector< Configuration > & autopas::AutoTuner::getConfigQueue

(

)

const

Getter for the current queue of configurations.

Returns

getCurrentConfig()

const Configuration & autopas::AutoTuner::getCurrentConfig

(

)

const

Get the currently selected configuration.

Returns

getEvidenceCollection()

const EvidenceCollection & autopas::AutoTuner::getEvidenceCollection

(

)

const

Getter for the internal evidence collection.

Returns

getNextConfig()

std::tuple< Configuration, bool > autopas::AutoTuner::getNextConfig

(

)

Ask the tuner for the next configuration to use.

This either returns the already selected config or triggers a step of the tuning process.

Returns

Tuple<Next configuration to use, still tuning>.

getTuningMetric()

const TuningMetricOption & autopas::AutoTuner::getTuningMetric

(

)

const

Getter for the primary metric for tuning.

Returns

getTuningStrategies()

const std::vector< std::unique_ptr< TuningStrategyInterface > > & autopas::AutoTuner::getTuningStrategies

(

)

const

Get the list of tuning strategies that are used.

Returns

inFirstTuningIteration()

bool autopas::AutoTuner::inFirstTuningIteration

(

)

const

Indicate if the tuner is in the first iteration of a tuning phase.

Returns

initEnergy()

bool autopas::AutoTuner::initEnergy

(

)

Initialize pmt sensor.

Returns

True if energy measurements are enabled and possible.

inLastTuningIteration()

bool autopas::AutoTuner::inLastTuningIteration

(

)

const

Indicate if the tuner is in the last iteration of the tuning phase.

Returns

inTuningPhase()

bool autopas::AutoTuner::inTuningPhase

(

)

const

Indicate if the tuner considers itself currently in a tuning phase according to its internal counters.

Returns

logTuningResult()

void autopas::AutoTuner::logTuningResult	(	bool	tuningIteration,
		long	tuningTime
	)		const

After a tuning phase has finished, write the result to a file.

Parameters

tuningIteration
tuningTime

needsHomogeneityAndMaxDensityBeforePrepare()

bool autopas::AutoTuner::needsHomogeneityAndMaxDensityBeforePrepare

(

)

const

Indicator whether tuner needs homogeneity and max density information before the next call to prepareIteration().

Returns

operator=()

AutoTuner & autopas::AutoTuner::operator= ( AutoTuner &&  other )

noexcept

Move assignment operator.

Parameters

other

Returns

prepareIteration()

bool autopas::AutoTuner::prepareIteration

(

)

Determines what live infos are needed and passes collected live info to the tuning strategies.

Note

The live info is not gathered here because then we would need the container.

Returns

Bool indicating if live Infos are needed before the next call to tune

receiveLiveInfo()

void autopas::AutoTuner::receiveLiveInfo

(

const LiveInfo &

liveInfo

)

Pass live info on to all tuning strategies.

Parameters

liveInfo

rejectConfig()

std::tuple< Configuration, bool > autopas::AutoTuner::rejectConfig	(	const Configuration &	rejectedConfig,
		bool	indefinitely
	)

Tell the tuner that the given config is not applicable.

Since this operation might change the suggestion what configuration to try next, this next suggestion is returned.

Note

The applicability checking logic was moved out of the tuner because it needed the container, thus raising the compile complexity.

Parameters

rejectedConfig
indefinitely	Whether the given config should be completely removed from the search space (aka rejected indefinitely).

Returns

Tuple<Next configuration to use, still tuning>.

resetEnergy()

bool autopas::AutoTuner::resetEnergy

(

)

Reset the rapl meter to prepare for a new measurement.

Returns

True if energy measurements are possible on this system.

sampleEnergy()

std::tuple< double, double, double, long > autopas::AutoTuner::sampleEnergy

(

)

Take an energy measurement.

Returns

Tuple<PsysEnergy, PkgEnergy, RamEnergy, TotalEnergy>

searchSpaceIsEmpty()

bool autopas::AutoTuner::searchSpaceIsEmpty

(

)

const

Indicator function whether the search space has no configurations in it.

Returns

searchSpaceIsTrivial()

bool autopas::AutoTuner::searchSpaceIsTrivial

(

)

const

Indicator function whether the search space consists of exactly one configuration.

Returns

setRebuildFrequency()

void autopas::AutoTuner::setRebuildFrequency

(

double

rebuildFrequency

)

Sets the _rebuildFrequency.

This is the average number of iterations per rebuild. This is used to dynamically change the _rebuildFrequency based on estimate in case of dynamic containers.

Parameters

rebuildFrequency

Current rebuild frequency in this instance of autopas, used by autopas for weighing rebuild and non-rebuild iterations

willRebuildNeighborLists()

bool autopas::AutoTuner::willRebuildNeighborLists

(

)

const

Returns whether rebuildNeighborLists() should be triggered in the next iteration.

This indicates a configuration change. In the non-tuning phase, the rebuildNeighborLists() is triggered in LogicHandler.

Returns

True if the current iteration counters indicate a rebuild in the next iteration due to a configuration change.

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The documentation for this class was generated from the following files:

• autopas/tuning/AutoTuner.h
• autopas/tuning/AutoTuner.cpp